What is your prefered commander, if you say tyrant then there is an excellent and well detailed post on that , which has plenty of juicy pointers you can use :
viewtopic.php?f=11&t=2160.
I think you need to be more flexible with your bo. There is no such thing as a one size fits all build.
But to tackle your current bo. Is there a particular reason you are building 2 standard warrior broods? 2 warriors is a useful build but it is also a specialized one that simply does not always work out on account of the large upkeep warriors have. I also dont need to tell you that neither warrior brood benefits from the synapse of the other so there is some inefficiency there. '
Gaunts are about 50% of the tyranid's much talked about resource efficiency. Most non gaunt nids have extremely high upkeeps. to the point where if you were to compare pop to pop nids are about 15 -20 more upkeep heavy than every other race. But gaunts are extremely pop efficent. to the point where a properly upgraded gaunt squad has almost the damage of other fully upgraded t1 melee/ranged squads almost the same hp (while under the proper synapse) but at almost half the pop ( 17 for sluggas vs 8 for a horma is a good example of this). Gaunts only really falter in damage type . but that is a minor issue.
I suggest going 3 gaunt 1 warrior 1 spore mine in t1 and then wait to see what your opponent does. Vs heavy infanty heavy races thropes are good , however thropes are not good vs terminators because terminators simply have too much hp for an arty unit like a thrope to scare them. on the other hand genestealers are extremely damaging when used right especially in counter initiation.
1 horma 2 terma is the standard. even thought pierce is not great vs heavy infantry the crippling poison on the termagants is damn near core to the race. it is simply too useful an ability to not have since it is 100% effective even into t3 vs things like terminators.
Keep in mind that most races try to single out your warrior broods when fighting a nid blob. this is true for both melee and ranged. So it is a good idea to melee say a terminator squad with every nid but your warriors and kite with the warriors. this keeps said warriors alive longer and prevents synapse pops.
If the opponent stops targeting the warriors .. then you can engage with them. but it is a gamble either way as terminators can easily tank a whole nid army and still pop a warrior squad if given the opportunity.
Vehicles are another issue with nids. according to the current patch notes , Cale wants to axe the thrope root ability. otherwise i would completely suggest using a thrope and a venom brood + whatever av option your commander has (crushing / venom for tyrant, devour for ravener and corrosive claws on lictor).
Nids only really have issues with battle tanks (similar to gk on this) because they dont have any long range av that can threaten said tanks until said tanks are in firing range. Chasing without the aid of a root (like the potentially removed thrope blast) is difficult for them.
every other tank . such as light support tanks, transports and dreads are not really an issue as they either have low enough hp that they will die before kiting is and issue or they simply cant kite.